Aw: Re: [RFC v1 5/5] arm64: dts: mediatek: Add mt7986 based Bananapi R3 Mini

Frank Wunderlich
2024-05-08T18:26:07Z

Hi

> Gesendet: Dienstag, 07. Mai 2024 um 15:35 Uhr
> Von: "AngeloGioacchino Del Regno" <angelogioacchino.delregno@collabora.com>
>
> Il 06/05/24 18:00, Frank Wunderlich ha scritto:

> >>> + fan: pwm-fan {
> >>> + compatible = "pwm-fan";
> >>> + #cooling-cells = <2>;
> >>> + /* cooling level (0, 1, 2) - pwm inverted */
> >>> + cooling-levels = <255 96 0>;
> >>
> >> Did you try to actually invert the PWM?
> >>
> >> Look for PWM_POLARITY_INVERTED ;-)
> >
> > Mtk pwm driver does not support it
> >
> > https://elixir.bootlin.com/linux/latest/source/drivers/pwm/pwm-mediatek.c#L211
> >
>
> You're right, sorry - I confused the general purpose PWM controller with the
> rather specific DISP_PWM controller (which does support polarity inversion).
>
> It's good - but I'd appreciate if you can please add a comment stating that
> the PWM values are inverted in SW because the controller does *not* support
> polarity inversion... so that next time someone looks at this will immediately
> understand what's going on and why :-)

so i would change comment like this:

/* cooling level (0, 1, 2)
* signal is inverted on board
* mtk pwm driver does not support
* PWM_POLARITY_INVERTED */

> >>> + pwms = <&pwm 0 10000>;
> >>> + status = "okay";
> >>> + };
> >>> +
> >>> + phy14: ethernet-phy@14 {
...
> >>> + interrupts-extended = <&pio 48 IRQ_TYPE_EDGE_FALLING>;
> >>> + reset-gpios = <&pio 49 GPIO_ACTIVE_LOW>;
> >>> + reset-assert-us = <10000>;
> >>> + reset-deassert-us = <20000>;
> >>> + phy-mode = "2500base-x";
> >>> + full-duplex;
> >>> + pause;
> >>> + airoha,pnswap-rx;
> >>> +
> >>> + leds {
> >>> + #address-cells = <1>;
> >>> + #size-cells = <0>;
> >>> +
> >>> + led@0 { /* en8811_a_gpio5 */
> >>> + reg = <0>;
> >>> + color = <LED_COLOR_ID_YELLOW>;
> >>> + function = LED_FUNCTION_LAN;
> >>> + function-enumerator = <1>;
> >>
> >> Why aren't you simply using a label?
> >
> > You mean the comment? I can add it of course like for regulators.
> >
>
> I mean in place of the function-enumerator... that's practically used to
> distinguish between instances, it's not too common to see it, and usually
> "label" replaces exactly that - just that, instead of a different number,
> it gets a different name with no (usually) meaningless numbers :-)

as far as i understand using label also makes "function" property useless, after discussing
this with eric i would drop both on all 4 places by labels like these:

label = "yellow-lan";
label = "green-lan";
...

not sure if we should drop color property too...

> >>> + default-state = "keep";
> >>> + linux,default-trigger = "netdev";
> >>> + };
> >>> + led@1 { /* en8811_a_gpio4 */
> >>> + reg = <1>;
> >>> + color = <LED_COLOR_ID_GREEN>;
> >>> + function = LED_FUNCTION_LAN;
> >>> + function-enumerator = <2>;
> >>> + default-state = "keep";
> >>> + linux,default-trigger = "netdev";
> >>> + };
> >>> + };
> >>> + };
> >>> +
> >>> + phy15: ethernet-phy@15 {
> >>> + reg = <15>;
> >>
> >> Same here.
> >>
> >> Cheers,
> >> Angelo

regards Frank